It is an extraordinary place. We still have a few minutes of walking to go and we reach the top of the Bure Plateau. We are at more than 2,000 m altitude and that’s it, we can see these huge parabolas pointing towards the sky. “You see the antennas that are observing, they point strictly to the same position in the sky”explains Frédéric Gutt, deputy director of the Institute for Millimeter Radio Astronomy (Iran).
These strange installed satellite dishes allow to detect radio waves from the universe, emitted by stars. The same waves that allow you to listen to the radio. They look at the same sourcesays Frederic Gutt. Sources in the sky emit light or waves. So we know the optical wavelengths. This is what our eye sees. But we have all heard of infrared, ultraviolet and then radio waves. We can study the processes of star formation, the dynamics of galaxies.”
This installation in the Hautes-Alpes is called Noema, after the extended millimeter array of the north. Eight years after the installation of its first antenna, the twelfth and last dish has just been put into service. This makes Noema the most powerful radio telescope in the northern hemisphere and the second most powerful radio telescope in the world after Alma in Chile and its 66 antennas. It is the result of a scientific project involving France, Germany and Spain. It will be opened on September 30 by Research Minister Sylvie Retailleau and her German counterpart.
On this plateau, obviously, there are these twelve antennas, but also a living base where the people who operate this radio telescope work and live and then a huge hangar. “This is the room in which the antennas were builtexplains the deputy director of Iram. All the antenna elements are assembled on the Bure Plateau and then the teams assembled everything to build this 120-tonne, 15m diameter antenna.
These parabolas move on rails. In recent months, the tracks have been extended to 1.7 km, allowing you to get a little closer. “We are here in the control roomdescribes André, one of the telescope operators. We are going to adjust the receivers, the antennas and so we go out to observe for five hours a group of eight galaxies that are very far away in the Universe, between 10 and 11 billion light years.
On these screens, a multitude of figures, graphs, these are the radio signals that astronomers like Edvige will later decipher. “We will translate the different frequencies into visible colors so we can see themexplains the astronomer. But in fact they will be false color images. In millimeters, we are sensitive to anything that is very cold, less than 170° Celsius, and we will see dust. And we will also be sensitive to the gas and mainly to the molecular composition of this gas.” And among the feats of arms of the Noema telescope, we find the observation of the most distant galaxy known to date.
The Noema radio telescope in Hautes-Alpes, the most powerful in the northern hemisphere, is receiving new antennas: Boris Hallier’s report